Field of the Invention
The present invention relates to a memory back-up apparatus and method for the back-up of the data stored in a memory of a control computer etc. and an audio and/or video data recording and reproducing apparatus for the back-up of indispensable data in a recording region of data by this memory back-up apparatus.
In the past, use has been made of an audio and/or video data server (video server) which has a recording apparatus using a randomly accessible recording medium such as a hard disc (HD) or magneto-optical disc (MO disc), records audio data and video data or either of them (audio and/or video data) in the recording medium, and can provide any part of the audio and/or video data to a video processing apparatus such as a video signal editing apparatus.
In such a video server, a real time property is required for the recording and reproduction of the audio and/or video data. Accordingly, data (recording region data) which is necessary for management of the recording regions of the recording medium is stored in the memory of the computer for controlling the recording apparatus so that high speed writing and reading of the data is possible and is used for the control of the recording apparatus.
However, for example, when the power supply stops and the recording region data stored in the memory of the control computer is lost, it becomes impossible to reproduce the audio and/or video data from the recording medium. In order to prevent such a situation, it is necessary to adequately back-up the contents of the memory of the control-use computer.
On the other hand, the memory of the control computer is frequently accessed during a period where the video server is operating. Therefore when the storage content is simply backed up regardless of the existence of the writing access, noncoincidence is caused between the contents of the backed up recording region data and the contents of the recording region data stored in the memory. Accordingly, it is necessary to back-up all of the recording region data stored in the memory at a certain point of time so as to maintain coherence of these data.